1. Field of the Invention
This invention pertains to the employment of a train of electrical pulses, each pulse having a positive portion of a shape different from its negative portion.
2. Description of the Prior Art
A repetitive pulse train wherein each pulse in the train is regular in shape, such as a spike, a rectangular shape, or a triangular shape, can be generated, measured and utilized in a scientific analysis or other applications using conventional procedures. The root mean square (rms) or average voltage value, similar current value or the like is measurable by conventional meters and standard generators are utilized to apply such pulse trains in scientific study or for some other useful application.
However, not all pulse trains utilize pulses of such waveshape. U.S. Pat. Application Ser. No. 095,009, Malcolm Skolnick et al, filed Sept. 8, 1987, which is incorporated herein by reference for all purposes, pertains to the measurement of pulses in a pulse train, wherein in a preferred embodiment each of the pulses have a rectangular positive polarity portion, a rectangular negative polarity portion and a portion of zero value. The amplitude of the positive polarity portion is much larger than the amplitude of the negative polarity portion and, correspondingly, the duration of the negative polarity portion is much longer than the duration of the positive polarity portion. The net charge transferred during an entire pulse delivered to a test object through which the current induced by the pulse is flowing under most conditions is zero but can be set to equal a predetermined constant. The '009 apparatus and method pertain to obtaining a meaningful value for a waveform wherein the net charge delivered by each pulse is zero. The rms or averaged meter value for this pulse is very much different from the average value of either the positive or negative pulse portions.
It is assumed in the '009 apparatus and method that the pulse train subject to measurement is independently generated from the meter used to measure the voltage, current or frequency parameters of the pulses in the train. However, there are many situations where the generation and the monitoring or tracking of the pulse train is a part of the same electronics package. That is, there are one or more predetermined characteristics of the pulses in the pulse train as such pulses are generated that make it possible to track the resulting voltage or current amplitude values, for example, by more direct means than can be accomplished when the generation means and the measuring means are completely separated and independent of one another.
Therefore, it is a feature of the present invention to provide for an improved method of generating and tracking a pulse train of repetitive pulses when the on-set time and the duration of each of said pulses is predetermined.
It is another feature of the present invention to provide an improved method of generating and tracking a pulse train of repetitive pulses by utilizing the average values of the voltage and/or the current for each pulse, which values are developed, in part, from predetermined knowledge of pulse on-set time and duration.
It is still another feature of the present invention to provide for the development of the averaged current and/or voltage value of a pulse in a repetitive pulse train by integration techniques and using one of such values for subsequent control of the same or different current and voltage values in a subsequent pulse.
It is yet another feature of the present invention to provide for the modification of a subsequent pulse from the averaged value of a preceding pulse, even when the pulse is comprised of unevenly shaped positive polarity and negative polarity portions, although the total charge delivered by the combination of the positive and negative pulses taken together as a single pulse complex is set to equal a predetermined value.
It is yet another feature of the present invention to provide for the determination and calibration of the values of operating parameters used in general operation of the system generating and tracking said pulses.
It is still another feature of the present invention to provide for the recognition of conditions when the corrections indicated necessary to modify the pulse amplitude are outside predetermined limits and to report these conditions as error messages.